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CHAPTER I. 



The COUNTRY between Warrina on the Great Northern Rail- 

 way and the Everard Range having already been explored and 

 geologically made known, I do not consider it necessary to give a 

 detailed report upon it, though a brief summary of my interpre- 

 tation of the geological phenomena may be expected from me. 



From Warrina to Cootanoorina, about twenty miles distant, 

 the surface-features are sandy ridges, trending north and south, 

 alternating with clay and loam-flats of considerable area. The 

 sands and loams overlie gypsum-bands and indurated gypsiferous 

 clays, which, when rising above the level of the plain, appear as 

 low flat-topped ridges. The wide flats bordering Arkaringa and 

 Laura Creeks are copiously covered with efflorescent salts. All 

 these deposits are of Newer Tertiary and Recent date. 



Between Nilpeua and Cootanoorina, whei'e the formation 

 changes from Tertiary to Cretaceous, mound-springs occur, which 

 yield an unlimited supply of good stock-water. 



Alongside Arkaringa Crekk, near Cootanoorina, extensive 

 gravel-beds exist, and the banks of the creek are composed of 

 calcareous sandstone. These stony downs and gravelly plains 

 continue as far as a line of elevated table-topped hills, which rise 

 about 1,000 or 1,200 feet above sea-level, and on an average 

 500 feet above the plain ; they are distant about 60 miles from 

 Warrina. The rocks of these table-topped hills comprise jasper- 

 rook, flinty (|uartzites, sandstone and conglomerate in horizontal 

 or slightly undulating beds ; the whole formation is of Cretaceous 

 age. About 110 miles west from Warrina the Cretaceous 

 formation is covered by red sands and loams of late Tertiary age, 

 which continue as superficial deposits to near Arcoellina Well, 

 157 miles from Warrina. Here Palasozoic rocks make their 

 appearance, consisting of quartzites, argillaceous slates and sand- 

 stones ; they rise in Mount Chandler and Chambers Bluif to a 

 considerable altitude, extend for a long distance in a S.W. direc- 

 tion, and are highly promising for mineral prospecting. Ten 

 miles west from Arcoellina, these rocks are concealed beneath 

 wide loamy plains, but re-appear to the south-east bordering the 

 main mass of the Everard Range, as gneiss and other schists. 



The Everard Range, which rises in Mount Illbillie to an 

 elevation of 3,010 feet above sea-level, consists entirely of coarse 

 granites appai'ently intruded among' the fore-mentioned Palaeozoics; 

 the depressed areas, which interrupt the continuity of the range, 

 are covered with loam and sand. The granitic rocks are inter- 

 sected occasionally, but more so in the southern portion of the 

 range, by dykes of diorite. Generally the granite contains 

 little 01' no mica, and a little only of hornblende. 



